1. Technical Field
This application relates to electronic equipment, and, in particular, to radio-frequency interference (RFI) and/or electromagnetic interference (EMI) shielding in electronic equipment, and methods of making electronic equipment with RFI and EMI shielding.
2. Discussion of Related Art
Electronic systems or modules can typically include one or more printed circuit boards (PCBs) populated with electronic circuits and devices. The PCB(s) can be contained within a housing which can have one or more covers which mate together to enclose the PCB(s). Similarly, one or more of the PCB(s) can mate with one or more of the covers of the housing. In some electronic systems or modules, it is important that the internal electronic circuitry be shielded from RFI and EMI, both to prevent RFI and/or EMI in the external environment from interfering with the internal electronic circuitry and to prevent the electronic systems or modules from emitting signals into the external environment.
Typically, to prevent RFI and/or EMI, the mating covers of the housing and/or the mating covers and PCB(s) of the system are made of or coated with a conductive material. When the covers are mated together or when the PCB(s) and cover(s) are mated together, an electrical gasket, which can also include a conductive material, can be interposed between them to provide an electrical seal. As a result, the circuitry can be completely enclosed by conductive material, which can be connected to the electrical ground of the system. This results in a complete shield against RFI and EMI.
In some electrical systems with such a shielding configuration, such as, for example, automotive radar sensor systems/modules, the gasket interposed between a PCB within the module and a cover of the module creates mechanical stresses on the PCB when it is attached to the housing cover. These stresses can cause damage to the PCB and can adversely affect the quality of the electrical seal and, therefore, performance of the system.